Top Ten Tree Problems

1. Borers

Borers are attracted to unhealthy trees, burrowing in and laying eggs under the bark. The best defense against borers is to keep your trees healthy and unstressed.

2. Diplodia/Dothistroma Blight:

Pine trees (especially Austrian pines) are susceptible to this disease, which causes needles to turn brown and die. Stressed trees with weakened defense systems, may not be able to combat this fungal disorder, in which case a fungicide could be used.

3. Scab Disease:

Complete defoliation in the middle of summer may occur as a result of this fungal disease, which affects ornamental and fruit trees in the rose family, particularly crabapples. Fallen, infected leaves should be raked up and discarded to prevent fungal spores from spreading. Spring fungicide applications will provide protection from this disease.

4. Girdling Roots:

These roots form as a result of planting trees too deep and nursery practices. Rather than growing outwards from the tree, these roots grow up towards the surface of the soil where air and water is more readily available. Eventually the root and tree trunk collide resulting in constriction of the trees transport system.

5. Japanese Beetle:

Readily found feeding on the upper side of leaves in summer, these insects can cause considerable damage. Adult beetles are most active in the afternoon, as they feed on flowers and foliage between the veins, leaving a lace-like skeleton behind.

6. Mites:

Mites pose a serious threat to a wide variety of plants, and can seriously impact the visual appearance of a plant. Mites favor warm or cool temperatures, dry climates, and are an extremely serious issue for many homeowners.

7. Scale Insects:

These insects target primarily hardwoods, conifers, and shrubs. Some signs of an infestation include abnormal leaf and shoot growth, yellow or red leaves, and branch swelling.

8. Anthracnose Disease:

This fungal disease affects deciduous and flowering trees. Look for a spotting of foliage in spring and summer.

9. Chlorosis:

A chlorotic tree will display a pale green leaf color within the canopy, as an outcome of the tree’s inability to manufacture enough chlorophyll. This can cause serious health implications and is often due to iron or manganese deficiencies within the tree.

10. Winter Injury:

Even during mild winters, evergreens can lose moisture and not be able to replenish it. Thus, make sure your evergreens have sufficient soil moisture. Antitranspirants applied to evergreens in fall will reduce moisture loss.